140,000 miles. New belt and pump 15k ago. Automatic P5. It's been super duper reliable. About 2 months ago, on the interstate and noticed the temp climbing, I bolted off into a gas station. It was hot by this point, but not steaming over. I went inside and bought a gallon of water. I let it cool, and slowly poured in water as not to shock cool it. Anyway, it took a gallon of water! I topped off the expansion tank as well. Paranoid, I drove the car to the next exit. It was ok. 10 more miles, ok. I drove the car for 1 more week, it was ok, but the reservoir was a little low. 1 month goes by of me just adding a little coolant to the reservoir. At this point, I smell antifreeze, but I can't pinpoint where it is going, but I smell it. Anyway, I was en route on the interstate and saw a wisp of steam at the hood /fender line. I pulled over, temp was ok... reservoir puked dry... Radiator had coolant, but the tank puked. When I got home, I snagged a thermostat. I tested it on the stove in water before installing. It popped at 190-205 consistently.
Now, I am not just going to keep refilling it, but I needed to hone in on the issue. Plugs looked good, it runs good, and the oil is clean. It is not getting coolant in the oil. Anyway, tonight on my way 4 hour road trip, I topped off the tank and set sail. I stopped for gas and the tank was low. I must have had to stop 3-4 times and put 2 gallons of water in the rad/tank. I have to be at work, I had no choice. It never ran hot, but it is puking out the tank. It seems to do it all at once. On my last stop, I filled it up, topped off rad and coolant tank. I drove another 30 minutes and checked. All good. All in all, I drove that last 1.5 hours and not 1 drop missing... WTF? I put cardboard under the car 3-4 times and it does not leak a drop. It only seems to be happening on the highway at 3,000 rpms at cruise. Now that I am 4 hours from home, I am trying to think of what is going on. What in the world would cause it to puke and puke and puke, and then just stop on the last 1.5 hours or so. New bad thermostat even though I boiled it and checked it? Radiator clogged and high rpms with the water pump turning fast it can't keep up with flow? I did a coolant flush when I put the thermostat in and it was nice and clean. What could this be guys?
Now, I am not just going to keep refilling it, but I needed to hone in on the issue. Plugs looked good, it runs good, and the oil is clean. It is not getting coolant in the oil. Anyway, tonight on my way 4 hour road trip, I topped off the tank and set sail. I stopped for gas and the tank was low. I must have had to stop 3-4 times and put 2 gallons of water in the rad/tank. I have to be at work, I had no choice. It never ran hot, but it is puking out the tank. It seems to do it all at once. On my last stop, I filled it up, topped off rad and coolant tank. I drove another 30 minutes and checked. All good. All in all, I drove that last 1.5 hours and not 1 drop missing... WTF? I put cardboard under the car 3-4 times and it does not leak a drop. It only seems to be happening on the highway at 3,000 rpms at cruise. Now that I am 4 hours from home, I am trying to think of what is going on. What in the world would cause it to puke and puke and puke, and then just stop on the last 1.5 hours or so. New bad thermostat even though I boiled it and checked it? Radiator clogged and high rpms with the water pump turning fast it can't keep up with flow? I did a coolant flush when I put the thermostat in and it was nice and clean. What could this be guys?